Dual Balloon Telescoping Guiding Catheter

ABSTRACT

A guiding catheter includes an inner guide movably disposed within an outer guide. Both inner and outer guides include inner and outer balloons, respectively, located at the distal tip of the guides. The inner guide balloon is fluted, thereby allowing blood to flow past the implanted balloon when inflated. The outer balloon is substantially annular in shape and is deployable as an occlusion balloon. Various sensors can be provided at the distal end of the guiding catheter to assist in locating a destination vessel or structure of interest.

RELATED PATENT DOCUMENTS

This application is a continuation of U.S. patent application Ser. No.10/132,093 filed on Apr. 25, 2002, to which Applicant claims priorityunder 35 U.S.C. §120, and which is incorporated herein by reference inits entirety.

FIELD OF THE INVENTION

The invention relates generally to surgical catheters, and moreparticularly to guiding catheters using balloons affixed to the distaltips of telescoping inner and outer guides.

BACKGROUND OF THE INVENTION

Catheters are used in a variety of medical procedures. In someapplications, these devices provide physicians the ability to explore,operate, and insert drugs/medical devices in various reaches of theanatomy without invasive surgery. Oftentimes, the catheters have medicaldevices mounted on the catheter shaft. For example, anelectrophysiological (EP) ablation catheter has an ablation electrodemounted at a distal tip of the catheter. In another application, guidingcatheters are used to create an easily navigable pathway to be used fordelivery of various payloads such as drugs, therapeutic/diagnosticdevices (e.g., EP mapping and ablation electrodes), and implantabledevices (e.g., cardiac pacing/defibrillation leads).

Guiding catheter systems are typically configured with a profile that isoptimized for the intended method of access. For example, when trying toaccess the coronary sinus of a patient's heart, one method is to enterthe venous system through an incision at a large vein such as thesubclavian vein near the shoulder. A guiding catheter is insertedthrough this incision and is sent in an arced path through the superiorvena cava into the right atrium of the heart. From the right atrium, theostium of the coronary sinus must be located. A catheter with a distalcontour including a relatively sharp bend will point the cathetertowards the likely location of the coronary sinus once the right atriumis reached. The contours of pre-shaped guiding catheters are often fixedduring manufacture.

A pre-shaped guiding catheter is sometimes used to blindly locate thecoronary sinus ostium. This endeavor, however, is complicated by thefact that the location of the coronary sinus ostium may vary appreciablyfrom one patient to another, especially among patients with diseasedhearts. If the pre-shaped catheter is introduced and found to be notwell adapted to the patient's anatomy, the catheter must be removed anda replaced with a catheter having a different shape. Replacing acatheter in this manner is time consuming, expensive, and can causeunnecessary trauma to the patient.

Even when the catheter has an ideal shape for a given application, thesize and flexibility of the catheter that provides maneuverabilitythrough a convoluted access path becomes a disadvantage when trying tomanipulate the distal end of the catheter in the right atrium. Further,once the catheter has cannulated the destination vessel, the flexibledistal tip may be dislodged from the destination vessel due to shapedistortions caused by introducing a payload through the catheter.

The primary objective of a typical guiding catheter procedure is tolocate and cannulate a vessel of interest in the least amount of time.Finding and cannulating the coronary sinus, for example, can become atime consuming, trial and error procedure even in a healthy patient.Patients exhibiting symptoms of advanced heart disease can haveblockages or deformations of heart structure, further complicating thetask of locating the ostium of the coronary sinus.

There is a need for an improved guiding catheter that provides for moreefficient access to vessels of interest, such as the coronary sinus.There is a further need for a catheter that can be positively secured ina cannulated destination vessel. The present invention fulfills theseand other needs, and addresses other deficiencies of prior artimplementations and techniques.

SUMMARY OF THE INVENTION

The invention relates to a guiding catheter for use in accessing variousanatomical regions, particularly the heart. In particular, a guidingcatheter of the present invention employs a telescopic arrangement ofinner and outer guides, with each guide provided with a controllablyinflatable balloon.

According to one embodiment, a guiding catheter of the present inventionincludes an outer guide having a pre-formed distal curve, a guide lumen,and an inflation lumen. The guiding catheter also includes an innerguide movably disposed within the guide lumen of the outer guide. Theinner guide includes an inflation lumen and can further include apre-formed distal curve. An annular balloon is fixably mounted to adistal end of the outer guide and in fluid connection with the inflationlumen of the outer guide. A fluted balloon is fixably mounted to adistal end of the inner guide and in fluid connection with the inflationlumen of the inner guide. At least two inflation mechanisms areprovided, each independently in fluid connection with the inflationlumens of the inner and outer guides. The inflation mechanisms are usedto selectively pressurize and depressurize a fluid within the inflationlumens to respectively inflate and deflate the annular and flutedballoons.

One or more sensors can be provided at a distal end of the guidingcatheter to assist in locating a destination vessel or structure ofinterest. A sensor can be mounted to the outer guide, the inner guide,or both the outer and inner guides. Useful sensor arrangements caninclude one or more of an optical sensor, infrared sensor, ultrasoundsensor, pressure sensor, temperature sensor, flow sensor, and oxygensensor.

According to another embodiment, a method for accessing a destinationvessel in a patient's heart according to the present invention involvesintroducing a distal end of a guiding catheter into a patient's accessvessel. The guiding catheter according to this embodiment includes anouter guide having a guide lumen and an annular balloon mounted to adistal end of the outer guide. The guiding catheter further includes aninner guide movably disposed within the guide lumen of the outer guide.The inner guide includes a fluted balloon mounted to a distal end of theinner guide.

The method further involves advancing the distal end of the guidingcatheter through a circulatory pathway, and distally extending the innerguide to engage the destination vessel with the distal end of the innerguide. The inner guide is distally extended to seat the inner guide inthe destination vessel. The fluted balloon is inflated to anchor theinner guide in the destination vessel.

According to a further aspect, after engaging the destination vesselwith the inner guide, the outer guide is distally advanced over theinner guide to engage the destination vessel with the outer guide. Theannular balloon is inflated to occlude blood flow. A contrast media isinjected into the guiding catheter for mapping blood vessels. Varioustypes of sensing can be employed at the distal end of the guidingcatheter to assist in locating a destination vessel or structure ofinterest.

The above summary of the present invention is not intended to describeeach embodiment or every implementation of the present invention.Advantages and attainments, together with a more complete understandingof the invention, will become apparent and appreciated by referring tothe following detailed description and claims taken in conjunction withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a catheter according to an embodiment ofthe present invention;

FIG. 2 is a side view of a distal end of the catheter according to anembodiment of the present invention;

FIG. 3 is a cross sectional view of an inner guide corresponding tosection 1-1 in FIG. 2;

FIG. 4 is a cross sectional view of an outer guide corresponding tosection 2-2 in FIG. 2;

FIG. 5 is a perspective view of the distal end of the outer guideaccording to an embodiment of the present invention;

FIG. 6 is a side view of proximal inflation mechanisms according to thepresent invention; and

FIG. 7 is a perspective cutaway view of a heart, illustrating a catheteraccording to the present invention cannulating the coronary sinus.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail herein. It is to be understood,however, that the intention is not to limit the invention to theparticular embodiments described. On the contrary, the invention isintended to cover all modifications, equivalents, and alternativesfalling within the scope of the invention as defined by the appendedclaims.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

In the following description of the illustrated embodiments, referencesare made to the accompanying drawings which form a part hereof, and inwhich is shown by way of illustration, various embodiments in which theinvention may be practiced. It is to be understood that otherembodiments may be utilized, and structural and functional changes maybe made without departing from the scope of the present invention.

In FIG. 1, a catheter according to the present invention, generallyindicated by reference numeral 100, is illustrated. The catheter 100utilizes a telescoping guide configuration that includes an inner guide102 movably disposed within an outer guide 104. The outer guide 104 hasa pre-formed curve 106 near a distal end. The pre-formed curve 106typically includes a shape optimized for the intended access path anddestination vessel. Fluted and annular balloons 108, 110 are fixablymounted to the inner and outer guides 102, 104, respectively.

The fluted balloon 108 includes fluted grooves 112 adjacent toinflatable sections 114. The fluted balloon 108 is inflated via aninflation lumen within the inner guide 102. The fluted balloon 108 isconfigured such that the inflatable sections 114 are enlarged uponinflation, the enlarged inflatable sections 114 gripping an interiorsurface of a blood vessel. The fluted grooves 112 allow some blood toflow past the inflated balloon 108, thereby preventing completeocclusion of the blood vessel. In this way, the fluted balloon 108 canadvantageously be used to secure the distal tip of the inner guide 102for a relatively long period of time without introducing problems causedby full blood flow occlusion.

The fluted balloon 108 may be formed similar to a standard latexocclusion balloon, with the additional application of longitudinaladhesive sections to the inside of the balloon 108. The adhesivesections bond an outer, inflatable member of the balloon 108 to theguide 102 to form the fluted grooves 112. The adhesive sections preventan area encompassed by the fluted grooves 112 from inflating whenpressurizing the balloon 108. The areas between adhesive sections serveas the inflatable sections 114.

An alternate configuration of the fluted balloon 108 may include bondinga plurality of elongated balloon sections lengthwise along the innerguide 102, each balloon section forming an inflatable section 114. Thespaces between balloon sections form the fluted grooves 112. Theelongated balloons can include a common fluid connection for inflation,such as a ring shaped manifold.

The outer guide balloon 110 (i.e., annular balloon) can be constructedsimilarly to occlusion balloons known in the art. The annular balloon110 is controllably expandable to substantially block the vessel inwhich the outer guide 104 is located, thereby occluding blood flow inthe vessel. For both balloons 108, 110, a fluid such as saline solutionis typically used to provide inflation pressure.

The inner and outer guides 102, 104 can be constructed using a varietyof techniques known in the art. The guides 102, 104 can be formed of anextruded polymer, such as Pebax thermoplastic elastomer resin. Otherpolymer materials, such as nylon and polyurethane, are also commonlyused for catheter guides. The guides 102, 104 may include regions ofdifferent material stiffness (e.g., durometer rating) to providecustomized performance. In a typical application, distal regions of theguides 102, 104 are fabricated to be relatively flexible, therebyallowing maneuverability through convoluted paths. A proximal region ofthe guides 102, 104 is made stiffer than the distal region, providingkink resistance and enhanced transmission of axial forces and torque.

As shown in FIG. 1, the pre-formed curve 106 is typically locatedproximal to the annular balloon 110. Various curve shapes are possible,the shapes being dictated by the destination vessel and access path ofinterest. The pre-formed curve 106 is made flexible such that the outerguide 104 straightens while being guided through the vasculature, yetresumes the pre-formed shape when a wider cavity, such as a heartchamber, is reached.

The inner guide 102 may also include a pre-formed shape 202 at a distalend, as seen in FIG. 2. The inner guide 102 can be made retractablewithin the outer guide 104 such that the inner guide's distal endsubstantially takes the shape of the outer guide 104 when retracted.When the inner guide 102 is extended such that the pre-formed curve 202extends beyond the outer guide's distal tip, the pre-formed curve 202resumes its original, pre-formed shape.

The pre-formed curves 106, 202 can be thermoset on the guides 102, 104in production. If the guide material does not take a thermoset, a jacketof thermoset or otherwise pre-formed material can be enclosed around adistal end of the guides 102, 104. The jacket causes the pre-formedcurve 106, 202 to conform to a desired shape.

Alternatively, a stylet 302, 402, best seen in FIGS. 3 and 4, made ofNitonol or other superelastic material can be affixed (e.g., bonded orenclosed) within a distal portion of one or both of the guides 102, 104.The superelastic properties of the stylet 302, 402 allow it to besubstantially deformed, thereby allowing the distal end to bestraightened for guiding through veins and/or arteries, then returningto the preformed shape when a desired access point is reached.

The guides 102, 104 may each include a braid 304, 404 as seen in FIGS. 4and 5. The braids 304, 404 are typically formed of fine stainless steelwires, although stainless steel ribbon and/or artificial fibers can alsobe used to form the braids 304, 404. The braids 304, 404 may cover allor part of the guides 102, 104, improving axial stiffness and kinkresistance therein with only a minimal reduction in maneuveringflexibility. The braids 304, 404 can be bonded or otherwise affixed toan exterior surface of the guides 102, 104. Alternatively, the braids304, 404 can be molded within the walls of the guides 102, 104.

The inner and outer guides 102, 104 typically include guide lumens 306,406. The outer guide lumen 406 is open throughout the length of theouter guide 104. The inner guide lumen 306 is typically open for guidingapplications, although an open inner guide lumen 306 may not be requiredif the inner guide 102 is not used to carry a payload. A lubriciousliner made from a material such as PTFE can be applied to an interiorsurface of the lumens 306, 406 to enhance passage of payloadstherethrough and movement of the inner guide 102 within the outer guide104.

The inner and outer guides 102, 104 contain additional lumens. Theguides 102, 104 at least contain inflation lumens 308, 408 that are influid connection with the distal balloons 108, 110. The inflation lumens308, 408 communicate a pressurized fluid from a proximal end to thedistal end of the guides 102, 104. The fluid is introduced at a proximalend of the guides 102, 104 and used for inflating the balloons 108, 110.A fluid connection between inflation lumens 308, 408 and balloons 108,110 can be created by forming an orifice through each outer wall of theguides 102, 104 into the lumens 308, 408. The balloons 108, 110 in sucha configuration each have an inflation opening, the opening beingpositioned over the orifice when the balloons 108, 110 are attached tothe guides 102, 104.

FIG. 5 illustrates proximal inflation mechanisms for the inner and outerguides 102, 104. The proximal end of the guides 102, 104 are fitted withvalves 502, 504 (e.g., hemostatic valves). The valves 502, 504 provide afluid seal for the guide lumens 306, 406, thereby helping to prevent thecatheter 100 from introducing an air embolism in the blood vessels. Thevalve 502 seals the inner guide 102 within the outer guide 104. Thevalve 504 seals any payloads that may be introduced through the innerguide lumen 306.

The valves 502, 504 also provide fluid connections between the inflationlumens 308, 408 and proximal inflation mechanisms 506, 508. The proximalinflation mechanisms 506, 508 may include a syringe or pump. Theinflation mechanisms 506, 508 may also include one or more pressuregauges to monitor the fluid inflation pressure.

Turning back to FIG. 4, an accessory lumen 410 is shown in the outerguide 104. The accessory lumen 410 is preferably extruded into the wallof the outer guide 104. The accessory lumen 410 can be used for carryingaccessory payloads such as injections and guide wires. The accessorylumen 410 can also be used to carry conductors or other communicationmedia coupled to a sensor attached to the outer guide's distal end.

Referring now to FIG. 6, an exemplary sensor configuration isillustrated on an outer guide 104. The sensor 602 can include asensor/transducer that measures pressure, temperature, flow, oxygen,infrared, and ultrasound. Miniature sensor assemblies are available inthe form of Micro-Electro-Mechanical Systems (MEMS) that areparticularly suited to this application. Such MEMS sensors/transducersare commercially available and adaptable to medical devices. Acommunication medium 604 is coupled to the sensor 602 and communicatessensor signals to measuring/processing equipment at the proximal end ofthe catheter 100. The communication medium 604 typically includes atleast one electrical conductor and can be disposed within the accessorylumen 410 of the outer guide 104.

An alternate sensor 602 includes a fiber optical sensor (e.g., lens) forsuch applications as thermal, visual, or laser-Doppler velocimetrysensing. The communication medium 604 in an optical sensor includes anoptical fiber that can be disposed within the accessory lumen 410. It isunderstood that a similar sensor and communication medium arrangementcan be provided for the inner guide 102, exclusive of, or in additionto, such an arrangement provided for the outer guide 104.

A catheter 100 according to the present invention has featuresparticularly useful in accessing anatomical features within the heart.An exemplary use of the catheter 100 is described hereinbelow relatingto accessing the coronary sinus, it being understood that other vesselsof interest can be similarly accessed in accordance with the principlesof the present invention. Coronary sinus access is often required inpacing/defibrillation lead implant procedures. Since the opening(ostium) of the coronary sinus into the right atrium is relatively smallcompared to the size of the right atrium, the coronary sinus is achallenging target vessel for cannulation.

Aspects of a coronary sinus access procedure are shown in FIG. 7.Catheterizing the coronary sinus 702 involves introducing the distal tipof the catheter 100 through an incision 704 into a percutaneous accessvessel 706. Common access vessels include the right cephalic vein andthe subclavian vein. The catheter 100 is advanced through access vessel706 into the superior vena cava 708, thereby entering into the rightatrium 710. From the right atrium 710, the catheter 100 can then locatethe coronary sinus ostium 712, thereby readying the catheter 100 forintroduction into the coronary sinus 702.

The clinician may utilize a sensor 602 in the outer guide 104 to assistin locating the coronary sinus ostium 712. For example, a flow sensor orDoppler sensor can sense the stream of blood exiting the coronary sinusbased on flow rate or flow velocity. A thermal or infrared sensor canlook for a higher temperature region indicative of the typically highertemperature blood leaving the coronary sinus 702. Other devices, such asa fiber optic camera or ultrasound transducer, can provide a visualrepresentation of the heart structure to aid in guiding the catheter100.

The catheter 100 can be maneuvered by extending and/or torquing aproximal end of the outer guide 104, thereby directing the guide'spre-formed distal end 106. The inner guide 102 can also be extended andtorqued to probe for the ostium at a distal end. By using the sensor 602and/or other means of visualizing the catheter 100 (e.g.,angiography/venography), a distal tip of the inner or outer guides 102,104 can be maneuvered to engage the ostium.

The outer guide 104 may include an accessory lumen 410 (as shown in FIG.4) that can accept a probing wire. The probing wire can be extendedthrough the outer guide 104 to assist in locating the ostium. Theprobing wire can include a distal curve that assumes a pre-set shapeupon extension from the outer guide 104, thereby providing an alternateshape to search for the ostium.

After the ostium is located, the outer guide 104 may be inserted intothe ostium. Alternatively, the inner guide 102 may be extended from theouter guide 104 into the ostium, thereby providing an extension of theouter guide 104. Once the coronary sinus is cannulated, the outer guide104 may be distally extended so that the annular balloon 110 is enclosedwithin the coronary sinus. The annular balloon 110 can then be inflatedto provide occlusion for a contrast injection. The contrast injectioncan be introduced through the inner or outer guides 102, 104, and isused for mapping branches of the coronary sinus (e.g.,venography/angiography), typically identifying a branch in which towedge a pacing/defibrillation lead.

After the contrast mapping is complete, the inner guide 102 is advancedinto position, the outer guide 104 is at least partially retracted, andthe fluted balloon 108 is inflated. As seen in FIG. 7, the inflatedfluted balloon 108 secures the inner guide 102 within the coronary sinusso as to prevent dislodgment, while advantageously allowing perfusion ofblood through the coronary sinus. After securing the inner guide 102, apayload can be introduced through the inner guide lumen 306 and into thecoronary sinus 702. After delivery of the payload (e.g., a pacing ordefibrillation lead implanted at a desired location), the catheter 100is properly retracted and removed from the patient's body.

It will, of course, be understood that various modifications andadditions can be made to the preferred embodiments discussed hereinabovewithout departing from the scope of the present invention. Accordingly,the scope of the present invention should not be limited by theparticular embodiments described above, but should be defined only bythe claims set forth below and equivalents thereof.

1. A guiding catheter, comprising: an outer guide, comprising: an outersurface having a circumference dimensioned to navigate into the coronarysinus and engage a destination vessel distal to, and smaller than, thecoronary sinus; a pre-formed distal curve configured to facilitatecannulation of the coronary sinus from the right ventricle andcannulation of the destination vessel by the outer guide; a guide lumendimensioned to receive an implantable cardiac lead; a distal regionflexible relative to a proximal region; and an inflation lumen; an innerguide movably disposed within the guide lumen of the outer guide, theinner guide comprising: an inflation lumen; a distal region flexiblerelative to a proximal region; a pre-formed curve on a distal end of theinner guide, the distal end of the inner guide having a circumference;and the inner and outer guides each configured such that the pre-formedcurve of the inner guide substantially takes the shape of the outerguide when the pre-formed curve of the inner guide is retracted withinthe outer guide and the pre-formed curve of the inner guide assumes itspre-formed shape when extended beyond a distal end of the outer guide;an annular balloon fixably mounted on the outer guide distal of thepre-formed distal curve of the outer guide and in fluid connection withthe inflation lumen of the outer guide, the annular balloon configuredto seal the coronary sinus and stabilize the inner guide in the coronarysinus in an inflated configuration by engagement with the coronarysinus; a fluted perfusion balloon fixably mounted to the inner guidedistal of the pre-formed curve of the inner guide, the fluted balloon influid connection with the inflation lumen of the inner guide andcomprising: a plurality of flutes arranged generally parallel to alongitudinal axis of the inner guide and configured to retain a flutedconfiguration sufficient to permit perfusion of fluid flow relative tothe fluted balloon when pressurized, and the fluted perfusion balloonconfigured to secure the inner guide within the destination vessel in aninflated configuration by engagement of the plurality of flutes with thedestination vessel sufficient to facilitate advancement of the outerguide over the inner guide to engage the destination vessel with theouter guide; and at least two inflation mechanisms each independently influid connection with the inflation lumens of the inner and outerguides, the inflation mechanisms facilitating pressurization anddepressurization of a fluid within the inflation lumens to respectivelyinflate and deflate the annular and fluted balloons.